sounds like it's going great! i'm one of those that have never separated new pets from current pets and like others, in my experience things calmed down after a couple weeks.
it helps A LOT when at least one pet just doesn't care if they're getting hissed or growled at lol

my avatar is a picture of Tucker laying in one of the kitchen table chairs. it's surrounded by windows and has become one of his favorite afternoon spots because he can doze and look out the window into the backyard. i'll post another pic when i can.

he has transitioned into the family wonderfully. our 5-yr old female can't stand him, acts like a snooty pants around him and he acknowledges that she is the Queen of the house and for the most part leaves her alone. our other female, a 4 yr-old solid black cat that is about 1/2 his size is his playmate. they get along wonderfully. he's just kind of a big clumsy Moose and we already love him so much!

very cute. happy it has worked out! we brought an adult german shepherd rescue into our home of 2 15 year old cats & their 16 year old mom. the dog never saw cats & the cats could not believe this enormous creature was moving in with them. after a few weeks of barking & hissing & swinging paws, my cats put my 90 lb dog in his place. from then on, he respected them. they were the boss. they figure it out on their own!